The panel has 15 days to conclude its investigations and report back to Dhagr.

The reports of abuses were revealed on Thursday in two separate investigations conducted by the Human Rights Watch (HRW) group and the Associated Press (AP) news agency.

HRW and AP said the UAE financed, armed and trained Yemeni forces that have arbitrarily detained, forcibly disappeared, tortured and abused dozens of people during security operations in the southern governorates of Aden and Hadramawt.

The UAE and the forces it created - the Security Belt force in Aden and the Hadrami Elite in Hadramawt - were accused of operating a clandestine network of prisons where hundreds are detained in inhumane conditions.

The revelations have prompted concern in Washington about alleged US complicity.

The UAE has denied the allegations.

US complicit?

In Washington, multiple senators called for an investigation after AP reported that US military interrogators had worked with the forces accused of torture.

The UAE is part of a Saudi-led coalition formed to help President Abd-Rabbu Mansour Hadi's government fight the Houthis and forces loyal to former President Ali Abdullah Saleh.

According to a July 2016 HRW report, the United States has been helping the coalition with "intelligence support and intelligence sharing, targeting assistance, advisory support, and logistical support, to include aerial refuelling with up to two tanker sorties a day".

The coalition is also helping the US target al-Qaeda and ISIL fighters in Yemen.

A member of the Hadrami Elite speaking anonymously to the AP said US forces were at times only metres away when torture occurred at the Riyan airport complex in the city of Mukalla.

The US defence department has denied any participation in or knowledge of human rights abuses.

Defence officials, however, confirmed to AP that US forces have interrogated some detainees in Yemen, and said that the US provided questions to UAE and received transcripts of their interrogations.

On Friday, John McCain, Republican chairman of the Senate Armed Services Committee, and the ranking Democrat, Jack Reed, called the reports "deeply disturbing" and urged Defense Secretary James Mattis to launch an immediate review.

"Even the suggestion that the United States tolerates torture by our foreign partners compromises our national security mission by undermining the moral principle that distinguishes us from our enemies - our belief that all people possess basic human rights," the senators wrote in a letter to Mattis.

"We are confident that you find these allegations as extremely troubling as we do."

Amnesty International said on Friday the US could be complicit in crimes under international law if it took part in interrogations of Yemeni prisoners or received information that may have been obtained through torture.

The American Civil Liberties Union said it has filed a Freedom of Information Act request for US records related to the interrogations.

'Political game'

Drawing on accounts from former detainees, families of people held in Yemen prisons, lawyers and Yemeni officials, HRW and AP said torture was rife in the informal prisons set up by the UAE and its allied forces, and included heavy beatings and sexual assault.

Former inmates told AP that blindfolded detainees were crammed into shipping containers at the Riyan airport detention complex. One man said he was tied to a horizontal pole and spun around inside a circle of flame, a torture method called "the grill".

According to HRW and AP, Yemeni officials and others have accused the UAE of moving some detainees out of Yemen to a remote Emirati base in Eritrea.